This specification relates to digital information retrieval.
Often a user may submit information to a service that provides a web page that includes content responsive to the information. For example, a search results web page can include search results provided by a search engine in response to a user's search query, or a mapping web page may include a map provided by a map service in response to a user's query for a map. For such web pages, additional content may be provided by another entity, such as advertisements provided by an advertisement server. The additional content is provided by content item servers in response to content item requests that are generated during the rendering of the web page by a client device.
In some cases, the identification of the additional content may depend on the content of the search results page, including the search results and related data. The additional content may therefore be requested asynchronously from the original search query based on info not yet available at the time the search results are initially presented to be served on the search results page. A search results web page is therefore served without the additional content.
In some cases, subsequent to the initial serving of the page, one or more pieces of additional content to serve are identified. For example, a maps service may wait until driving directions results have been computed so that it can use route information to target advertisements. Often some of the additional content will displace content already present on the page. For example, if an advertisement that is served is to be rendered at a location that will displace previously rendered content (e.g., a “top” position advertisement), the resulting displacement of the previously rendered content creates a “blink-in” effect. As used herein, the term “blink-in” refers to the displacement of previously rendered content from a first location to a second location and the rendering of additional content that is received subsequent to the rendered content in the first location. Unexpectedly moving content on the page to accommodate this additional content may degrade the user's experience.